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Buying the Best Concrete Grinder (Top 5 Picks for 2018)

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Image Credits: Bosch.com

What is the best concrete grinder on the market in 2018? That’s exactly what we look into today.

We have taken 5 top rated grinders and dived deep to give you a comprehensive low down on each.

For our findings at a glance, just check out the table below. For an in depth review of each grinder plus a dedicated buyer’s guide, keep on reading.

The all important grinding disc

Diamond tools refers to diamond-studded materials that are bonded onto the grinding disc.

The most common diamond tool used in concentrate grinders is the diamond grinding cup-wheel.

This is a cup-shaped grinding disc on which is attached, using metal-bonding, at least a row of diamond segments (usually there are 8 diamond segments in each row).

These abrasive materials allows the grinding disc to rub off (abrade or rub down) the top layer of the concrete (or any other) surface being worked on by the concrete grinder.

This implies that grinders cannot be used to cut or bore holes into concrete surfaces, and they are usually used to grind away up-to 1/8 inches of the concrete (material) thickness.

Depth of Grind

The depth of grinding action depends on the configuration of concrete grinder used.

The walk-behind grinder is a large machine that feature rear wheels that allows it to be wheeled around the working area, and it is therefore suitable for working on large slabs.

The depth of grind is deeper due to the industrial nature of the machine; they are designed to cover large areas faster.

The small models come as single-disc units, while the medium-duty model come as dual-disc or triple-disc model.

In the dual-disc model, the two grinding discs are placed side-by-side so as to grind more surface per unit time.

Size of the disc

There are also four-disc units which are usually labeled as heavy-duty concrete grinders as they are designed to perform high-production grating and polishing of large slabs.

The size of the grinding disc usually ranges between 10 to 12 inches in diameter. Therefore, the dual-disc unit can grind 20-24 inches of surface per pass, while triple unit can grind about 30 inches per pass.

In multiple-discs unit, there is a gear unit attached to the hub (or central axial rod) that rotates each disc.

These gears mesh with each other, as well as mesh with the gear fitted on the motor hub.

Therefore, when the motor spins, its rotating motion is immediately, and also simultaneously, transmitted to all the rotating grinding discs.

Depending on the gear orientation, in dual-disc units, one disc can rotate clockwise, while the other rotates anti-clockwise, and this serves to reduce the side-swinging motion of the grinder.

Dry or wet grinding

Normally, grinding discs can handle lots of stress as they need to overcome the sliding friction of the surface materials in order for them to strip away the top layers of the concrete surfaces.

However, if this grinding is done on a dry concrete floor it can cause a cloud of fine concrete dust to be released during the process of dry grinding. Workers in the area can end up inhaling this dust as a result.

For this reason, most concrete grinders used for dry grinding come with a hooked dust bag which sucks dust away from the work-area the moment it is released.

Another way to reduce dust generation is to wet the surface to be grated with a thin layer of fluid, and the subsequent grinding is described as wet grinding.

The hand held options

Image Credit: Bosch.com

Hand-held concrete grinders are lightweight, portable, and compact grinding tools designed to be carried around the workplace, as well as reach confined spaces.

Rarely do hand-held grinders have more than one disc, as this would make them bulky and difficult to use as workers would have their hands swung from side to side by the motion of rotating grinding discs. The size of these grinding discs are either 5 inches or 7 inches.

Gas or electric?

Concrete grinders can be electrically-powered or gas powered.

Electrically-powered grinders use either single-phase or three-phase motors, while gas-powered grinders are usually run by either propane-fed or gasoline-fed single cylinder engines.

The speed of rotating discs, and depth of abrasion determine the quality of work.

Best Concrete Grinder – Top 5 Reviews

Image Credit: Bosch.com

There are different models, types, and brands of concrete grinders. For our round up we have selected 5 top rated models across a range of cost point, size and power. What follows is our in depth reviews of each of our picks.

This portable concrete grinder features a compact easy-to-handle design. It measures 19.8 inches in length and 14.8 inches in width, with its overall height estimated at 10.8 inches if the auxiliary handle is upright.

It weighs about 23 pounds, which makes it lightweight to use. Its compact design and size allows the user to grind and polish surfaces located in tight spaces.

The grinder has a single grinding disc which is a 5-inch diamond grinding cup-wheel. This cup-wheel can be detached and replaced as and when required.

The 5-inch cup-wheel is designed for universal usage with its steel body construction featuring 5 equally-spaced large holes, as well as being capable of absorbing vibrations. The cup-shaped design also allows it to efficiently dissipate heat hence reducing chances of heat build-up and malfunction.

The design and spacing of the holes are meant to optimize dust extraction for the working surface as it allows airflow to carry particulate debris into the dust-collection shroud.

Two types of 5-inch cup-wheels are designed to fit in this model; the 11 diamond segments model and the turbo-continuous rim model.

In the 11-diamond segments model, 2 rows (6 segments in the outer row and 5 segments in the inner row) of high-grade, high-density diamond segments are metal-bonded to the cup-wheel.

This particular type of diamond grinding cup-wheel is designed for polishing and texturing surfaces as well as removal of coats and shallow hardened grits. As a result, this model can be used as a surface grinder.

On the other hand, the turbo-continuous rim design is purposely built for efficient grating of hardened dense concrete, marble, and granite surfaces; and it creates a smooth profile as it mostly polishes the surface rather than abrade it.

This model features an easy-to-use spindle lock which allows for easy changing of the cup-wheel.

The auxiliary handle is well-positioned and prominent enough to allow the user to have a steady grasp on the machine, hence enabling the worker to easily steady the grinder during use.

The grinder is rated as versatile as it can work on both dry and wet surfaces include dense concrete surfaces.

This single-disc portable hand-held unit is powered by 12.5 amperes of electricity which enables the grinding disc to rotate at 9,300 revolutions-per-minute (rpm).

Our top pick grinder also has an electric cable that extends from the tool, and goes on to terminate in a top-plug, that is used to connect the machine to an AC power outlet.

The existence of an electric cord means that the grinder can be used as far away from the power socket as the the cord permits, and this limits the range of areas that can be worked on.

Even so, if the user needs to reach tight places located far away from the power socket, an extension cable can be attached to the electric cord of the grinder.

This model can easily handle dry grinding as it features a dedicated dust-guard system which allows it to easily collect dust that is generated when the grinding wheel flushes against the work surface.

This dust-guard system features 3 main components, the surface guard, the vacuum adapter, and the dust-collection shroud.

The vacuum adapter is attached to the surface guard so as to ensure that the surface guard has a vacuum connection.

This vacuum connection terminates in the dust-collection shroud which harvests the dust when it is created as the disc peels off the top layer of the surface.

This real-time dust collection ensures that the work surface is clean, hence allowing the user to easily ascertain whether the surface has been properly prepared.

The Bosch is built for a long operational life with its motor casing and switch housing being completely sealed off to prevent dust from accumulating within these enclosed spaces, and damaging the motor and switch functions.

The motor hub rotates on double-sealed ball bearings, with the two lip-sealing rings around the axial shaft of the rotor preventing dust from creating an insulation layer between the power-input rings and the rotor.

These sealing features ensure that the motor operates within a dust-free environment hence reducing wear-and -tear as well as eliminating instances of motor knocking or loss of power.

The electric motor in this model is built using the proprietary Constant Response circuitry which allows the motor to handle different operational loads as the grinding disc is pressed on different surfaces.

This motor requires 120-volts AC power to run. The lock-on/off switch in this grinder allows for easy operation of the motor.

This model comes with a limited 12-months warranty guaranteed by Bosch Tools. It is shipped alongside a flange kit, carrying case, and a spanner wrench.

Pros of the Bosch CSG15 Concrete Grinder

Can dry grind as well as wet grind.

Excellent dust collection.

Easy to use and maintain

Ergonomic design.

Grinding disc made of high-quality abrasive material.

Sturdy, durable motor powers the grinding disc.

Benefits from 12-months limited warranty.

The Cons

Area of operation limited by length of electric cord.

Bottom-line

The Bosch CSG15 is a high-quality, high-performance concrete surfacing grinder that features a 5-inch diamond grinding cup-wheel, sealed motor casing, and an efficient dust-guard system.

The Metabo is a portable, hand-held single-disc concrete preparation kit that features a dust-control shroud.

It is a versatile concrete grinder that can be used for concrete preparation and metal surface grating. As the name indicates, it is manufactured by Metabo Power Tools, a Germany-based manufacturer of high-quality concrete grinders.

This portable concrete grinder features a compact easy-to-handle ergonomic design. It measures 23 inches in length and 16 inches in width, with its overall height estimated at 8 inches if the auxiliary handle is upright.

This makes it slightly larger than Bosch CSG15, but with a smaller auxiliary handle. The Metabo US606467800 weighs about 22 pounds, which makes it as heavy as Bosch CSG15. Like our top pick it is a handheld option designed with portability in mind.

As such, the compact size of the Metabo allows the user to grind and polish surfaces located in tight spaces.

The Metabo Concrete Grinder has a single grinding disc. This disc is a 7-inch diamond grinding cup-wheel which makes is the largest of the handheld options in our top 5.

This cup-wheel can be detached and replaced after becoming worn.

The cup-wheel is designed for universal usage with its metal body construction featuring 8 equally-spaced large holes, arranged around a large central hole.

The cup wheel also features a double row of metal-bonded diamond segments with 8 segments in each row. The cup-shaped design allows it to absorb vibrations as well as efficiently dissipate heat hence reducing chances of heat build-up.

The design and spacing of the holes are meant to optimize dust extraction.

The other design of diamond grinding cup-wheel that can fit in the Metabo concrete grinder is the turbo-continuous rim cup-wheel design.

This model can therefore be used for polishing and texturing surfaces as well as removal of coats and small hardened grits.

If the turbo-continuous rim cup-wheel is used, then the grinder can be used for grating and smoothening hardened dense concrete, marble, and granite surfaces.

The grinder also features an easy-to-use spindle lock which allows for easy changing of the cup-wheel.

The auxiliary handle features the proprietary Metabo VibraTech vibration-damping design which ensures that vibration from the work surface are not transmitted into the hands and arms of the worker.

This handle is also well-positioned and prominent enough to allow the user to have a steady grasp on the machine, hence enabling the worker to easily steady the grinder during use.

Both dry and wet surfaces include dense concrete surfaces can be worked on with the Metabo, making it just as versatile as our top pick Bosch.

The single-disc portable hand-held unit is powered by 15 amperes of electricity which enables the grinding disc to rotate at 6,600rpm.

The model is powered by a mains outlet and AC supply. Inevitably, the electric cord limits the range of areas that can be worked on. (However, an extension cable can be attached if required.)

The Metabo US606467800 can handle dry grinding with ease as it features a dedicated dust-control system.

This allows it to easily collect dust that is generated when the grinding wheel flushes against the work surface.

As with the Bosch concrete grinder reviewed above, the dust-control system features a surface guard that is attached to a vacuum adapter. This in turn is connected to a dust-control shroud.

This ensures that dust is harvested as it is created. This real-time dust collection ensures that the work surface is clean, which maximises safety as well as results.

The grinder is built for a long operational life with its sturdy and durable Metabo-made Marathon motor featuring auto-stop carbon brushes.

The winding protection ensures that dust, dirt, and debris are deflected away from the armature windings of the motor. The gear system that links this motor to the hub of the grinding disc is housed in a die-cast aluminum casing.

There is also a lock-on/off switch which allows for easy operation of the motor. Moreover, this motor can handle different operational loads as the grinding disc is pressed on different surfaces.

The DWE46153 is a portable, hand-held single-disc surface grinding kit that features a dust shroud. Like the options reviewed above, it is a versatile, handheld concrete grinder that can be used for both concrete preparation and surface polishing. It is manufactured by DeWalt.

This portable concrete grinder features a compact easy-to-use ergonomic design. It measures 18. inches in length and 6.8 inches in width, with its overall height estimated at 5.4 inches if the auxiliary handle is upright.

This makes it smaller than Bosch CSG15 and actually easier to carry around and control.

The DeWalt DWE46153 weighs about 8.5 pounds, which makes it extremely light-weight as compared to either the Bosch CSG15 or the Metabo US606467800. It also makes it the most portable concrete grinder among the three models.

Its compact design and small size allows the user to grind and polish surfaces located in tight spaces.

The DeWalt has a single grinding disc. Like the Bosch reviewed above, this disc is a 5-inch diamond grinding cup-wheel, which can be detached and replaced as needed.

The cup-wheel is designed for universal usage with its metal body construction featuring equally-spaced large hole.

The cup-wheel is of the turbo-continuous rim design which allows this model to smoothly grate and smoothen hardened dense concrete, marble, and granite surfaces.

The cup-shaped design of the grinding disc allows it to absorb vibrations and dissipate heat. The design also optimizes dust extraction as the airflow helps to carry debris into the dust-collection shroud.

The DeWalt DWE46153 has an easy-to-use spindle lock which allows for easy changing of the cup-wheel.

It also features a quick-change wheel release mechanism which allows for the grinding disc to be replaced without the worker using tools such as a wrench. Likewise, the grinding disc is well adapted for flush-edge grinding.

The DeWalt DWE46153 can be used for dry grinding with its dedicated dust-control system.

This dust-control system features a surface guard that is attached to a vacuum adapter that is in turn connected to a dust-control shroud.

Not only does this ensure that dust is harvested as it is created, the dust shroud features universal connection locks making everything nice and simple to use and maintain.

The universal connection locks for the vacuum hose allows standard types of vacuum hoses to be connected to the dust collection shroud through a simple twist-and-click mechanism which obviates the need for taping the hose to the shroud.

The concrete grinder also comes with a unique flush-grinding door which is designed to allow for dust collection during flush-edge grinding.

This is a portable, hand-held single-disc concrete grinding kit that features a dust-collection shroud. It is versatile as it can be used for surface preparation, concrete grinding and surface polishing. It is manufactured by Robert Bosch Tool Corporation.

Its design features and internal components are almost similar to those of the Bosch CSG15 with the major difference being that the Bosch 1773AK can achieve 11,000rpm while the CSG15 is limited to a maximum of 9,300rpm.

The Bosch 1773AK is a portable concrete grinder that features a compact easy-to-carry design. It measures 19.8 inches in length and 14.9 inches in width, with its overall height estimated at 10.6 inches if the auxiliary handle (bail handle) is upright.

It is therefore almost the same size as our top pick CSG15. However, the Bosch 1773AK weighs about 14.9 pounds (as compared to Bosch CSG15 which weighs 23 pounds), making it much lighter and more portable than the CSG15.

This ultra lightweight and compact design allows the user to grind and polish surfaces located in tight spaces.

Just like the Bosch CSG15 grinder, the Bosch 1773AK model has a single grinding disc, which is a 5-inch diamond grinding cup-wheel.

This cup-wheel can be detached and replaced. The 5-inch cup-wheel is designed for universal usage with its steel body construction featuring 5 equally-spaced large holes, as well as being capable of absorbing vibrations, while its cup-shaped design allows it to efficiently dissipate heat hence reducing chances of heat build-up.

The design and spacing of the holes are meant to optimize dust extraction for the working surface as it allows airflow to carry particulate debris into the dust-collection shroud.

However unlike the Bosch CSG15 which can use either the 11-diamond segments grinding disc or the turbo-continuous rim disc; the Bosch 1773AK model works best with the 11-diamond segments grinding disc.

This makes the Bosch 1773AK suitable for polishing and texturing surfaces, as well as removal of coats and shallow hardened grits. It can also be used for grating and smoothening of dense concrete, marble, and granite surfaces.

The Bosch 1773AK features an easy-to-use spindle lock which allows for easy changing of the cup-wheel. This spindle lock features proprietary Service Minder brushes, and a unique wrap-around mechanism that allows it to wrap around the auxiliary handle.

The auxiliary handle is well-designed to allow the user to have a steady grasp on the machine. This grinder can work on both dry and wet surfaces include dense concrete surfaces.

The Bosch 1773AK is powered by 1o amperes of electricity which enables the grinding disc to rotate at 11,000rpm. Its electric cord terminates into a top-plug, which connects to an AC power outlet.

The Bosch 1773AK handles dry grinding well because it has a dust-guard system that allows it to easily collect dust as it is produced by the flushing action of the grinding wheel on the work surface.

The dust-guard system has a surface guard onto which is fitted a vacuum adapter. The dust-collection shroud covers the entire grinding disc unit.

Just like the Bosch CSG15 grinder, the 1773AK model is built for a long operational life with its motor casing and switch housing being completely sealed off to prevent particulate dust from accumulating within these enclosed spaces, and impinging the motor and switch functions.

The motor hub rotates on double-sealed ball bearings, with the two lip-sealing rings around the axial shaft of the rotor preventing dust from creating an insulation layer between the power-input rings and the rotor. These sealing features ensure that the motor operates within a dust-free environment.

Also, just like in the Bosch CSG15 grinder, the electric motor unit in this model is built using the trademarked (proprietary) Constant Response circuitry which allows the motor to handle different operational loads as the grinding disc is pressed on different surfaces.

This motor requires 120-volts AC power to run. The lock-on/off switch in this grinder allows for easy operation of the motor.

This model comes with a limited 12-months warranty guaranteed by Robert Bosch Tool Corporation. It is shipped alongside a flange kit, carrying case, and a spanner wrench.

Our final review is that of a single-disc walk-behind concrete floor grinder, featuring a complete MK IXL dust collection shroud and a 7-inch diamond grinding cup-wheel.

The dust collection shroud is connected to a vacuum hose. Furthermore, the entire concrete grinder unit can be wheeled around the work-place using its two rear wheels. This model is made by MK-Diamond Products, Inc.

The MK-Diamond 166859 MK-SDG-7 is a lightweight walk-behind model that features an easy-to-use ergonomic handle bars that can be removed when necessary.

It weighs about 44 pounds, which makes it quite a lightweight product to push around the workplace.

The concrete grinding unit measures 34.6 inches in length and 32 inches in width; while its average height is 17.5 inches.

This is a walk-behind model, and this means that its can move around at two speed ranges. The first speed ranges is the transport speed range which requires the user to disengage the grinding disc from the floor so that the unit can be transported for storage.

The transport speed range is higher than the working speed range. The working speed range is the movement speed that the user sets when the unit is being used to grind concrete or granite floors.

It is important that the right speed range is chosen as selecting the transport speed range during concrete grinding procedures not only ruins the floor, but can cause dangerous slips of the machine which can seriously injure the user.

The MK-SDG-7 uses a single grinding disc, which is a 7-inch diamond grinding cup-wheel. This cup-wheel is a single row diamond segments grinding disc that can be detached and replaced as required.

The metallic body construction of this cup-wheel features equally-spaced large holes that allow for optimum dust extraction from the work surface.

Likewise, the cup-wheel design allows the grinding disc to absorbing vibrations, as well as efficiently dissipate heat. This walk-behind model is suitable polishing and texturing floors, as well as removing coats and hardened grits on concrete floors.

Even so, it can still be used for grating and smoothening of dense concrete, marble, and granite floors.

The MK-SDG-7 runs using a 115-volts, 15-ampere AC motor that can spin the grinding disc to speeds of up-to 3,500rpm.

This walk-behind unit handles both dry grinding and wet grinding of concrete floors exceptionally well. Its dust guard system features a surface guard onto which is fitted a vacuum adapter, with the dust-collection shroud covering the entire grinding disc unit.

This shroud is then connected via a vacuum hose to a large-capacity dust collection bucket; and this allows this walk-behind unit to cover more area per unit time as compared to the 4 hand-held concrete grinders reviewed above.

Pros of the MK-Diamond 166859 MK-SDG-7 Concrete Grinder

Can perform both dry grinding and wet grinding exceptionally well.

Excellent dust collection.

Can cover a larger area as compared to hand-held concrete grinders.

Ergonomic design.

Grinding disc made of high-quality abrasive material.

Sturdy, durable motor powers the grinding disc.

The Cons

A number of customers have had problems with the unit on arrival. Proper setup is required in order to get the best out of the machine.

An expensive option better suited to commercial grinding applications

It is advised that customer reviews are taken into account before purchase as results have differed across many users.

Bottom-line

The MK-Diamond 166859 MK-SDG-7 is a single-disc walk-behind concrete floor grinder that features a complete MK IXL dust collection shroud and a 7-inch diamond grinding cup-wheel.

This portable concrete grinder unit can be wheeled around the work-place using its two rear wheels. It has its problems however, and performance can be less than high quality without the correct set up.

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